Method of producing compression molded candles

ABSTRACT

A method and apparatus for forming a candle from a particulate wax material utilizes a compressive force of at least 2,000 p.s.i. to form the material into a self-sustaining body for a freestanding candle comparable in strength and appearance to a cast candle of the same size. The extremely high pressure forms the particulate material into a candle body wherein the amount of entrapped air is minimized for maximum color density and elimination of granular surface appearance as opposed to prior methods of compression molding where only partial compression resulted in candles each having a surface where the particulate nature of the starting wax material is clearly visually evident. The method is carried out utilizing an open-ended mold, one end of which has been closed and into which a wick rod has been inserted for forming a wick hole in the candle blank. Particulate wax material is introduced into the mold and a piston is moved against the material under a pressure of 2,000 to 10,000 p.s.i. The closed end of the mold is then opened after which the candle blank is ejected. A candlewick is then inserted into the hole in the blank to complete the candle.

United States Patent [1 1 5 Renoe [4 Nov. 14, 1972 METHOD OF PRODUCING[57] ABSTRACT COMPRESSION MOLDED CANDLES A method and apparatus forforming a candle from a [72] Inventor: Ronald R. Renoe, Mission, Kans.particulate wax material utilizes a compressive force of at least 2,000psi. to form the material into a self- [73] Asslgnee. c z r hfIncorporated Kansustaining body for a freestanding candle comparable Sasin strength and appearance to a cast candle of the [22] Filed: Sept. 8,1970 same size. The extremely high pressure forms the particulatematerial into a candle body wherein the [21] Appl' 70390 amount ofentrapped air is minimized for maximum color density and elimination ofgranular surface ap- 52 US. Cl. ..29/428, 264/102, 264/109, pearance asopposed to prior methods of compression 2 4 319 molding where onlypartial compression resulted in 51 Int. Cl. ..,..B2sb 3/02 candles eachhaving a Surface Where Pamieulate [58] Field of Search ..431/288;264/102, 109, 319, name of Stming Wax material is clearly visually264/334; 18/1 K, 27 2 425 29/428 evident. The method is carried oututilizing an open- J ended mold, one end of which has been closed and[56] References cued into which a wick rod has been inserted for forminga wick hole in the candle blank. Particulate wax materi- UNITED STATESPATENTS al is introduced into the mold and a piston is moved against thematerial under a pressure of 2,000 to K PIS-i. The closed end of themold is then Heinflch opened after the candle is ejected. A 3,026,572Reick X dlewick is then inserted into the hole in the blank to 2,679,0695/1954 Keogh ..l8/l K complete the Camila Primary Examiner-Robert F.White 19 Claims, 6 Drawing Figures Assistant Examiner-T. E. BalhoffAtt0rneySchmidt, Johnson, Hovey, Williams and Chase Compression 5T anon3 fiorgriressiom- Wick Rod Holder" 0 s Fi c: a 222 36 E/ v WlCk R5213Die -12 Piston Die Assembly Candle 24 6 Support Rail Blank 6% /l 32 46Die Plate f/Plof PATENTEDWW H 5,702,495

2 i o 2 Wick Rod Holder Wk Rod Holder 17 .2.

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/l l 32 i l Mfl,; p 1 i Die Assembly I! Suppor 94 Q \fl Die Plole p t 4L 48 s s 46 i 40 46 6* Candle Blank 66 7 Candle Die Plafe 50 ?%"BlonkINVENTOR. 54 Ronald R. Renoe wlCk g- 7 BY //Spike Hole W F 8.6. w 92:?

ATTORNEYS.

METHOD OF PRODUCING COMPRESSION MOLDED CANDLES This invention relates toa method and apparatus for the compression molding of wax candles.

Prior to this invention, highest quality candles were obtained bycasting molten wax into a candle mold, a major disadvantage in thecasting process is the time required for the molten wax to cool andsolidify to permit handling of the candle. Another disadvantage inherentin casting processes for producing candles is the tendency for voids tooccur in the central part of the cast candle body, thus causing the wickaround which the wax is cast, to be drawn off center and resulting inerratic burning properties. Thus, in the interest of economy, effortshave been made to develop a method of forming candles wherein a moreperfect product is produced while at the same time eliminating thetimeconsuming step of cooling the molten wax in a mold therefor. Coolingtimes of up to 12 hours for large cast candles is common in theindustry. Processes suggested as alternates to casting have generallybeen unable to produce a candle of equivalent density to a cast candle,thereby resulting in inferior burning qualities and decreased physicalstrength. On the other hand, compression molding of candles has manyadvantages over coasting techniques, particularly from the standpoint ofbeing able to provide polychromatic candles to an extent not possiblewith casting. Because of the limitations of prior methods of compressionmolding of candles, such method has been largely limited to formingcandles of the religious votive type which are adapted to be supportedby auxiliary structure and the melted candle wax contained in areceptacle therefor. Such techniques have generally not been applicableto freestanding candles.

It is, therefore, a principal object of the present invention to providea method and apparatus for compression molding a candle body fromparticulate wax material wherein the material is coalesced undersufficient pressure to produce a freestanding candle having burning,strength and physical appearance characteristics comparable to a castcandle of the same size and color.

Another object of the invention is to provide a method and apparatus forcompression molding a candle body from a particulate colored waxmaterial wherein the material is coalesced under sufficient pressure toremove substantially all entrapped air and produce a candle of superiorcolor as a result thereof.

A further object of the invention is to provide a method and apparatusfor compression molding a candle from a particulate wax material whereina candle of superior strength and resistance to warping is obtained bycoalescing the particulate material under a compressive force of atleast 2,000 p.s.i.

It is also an object of the present invention to provide a method andapparatus for compression molding a candle from a particulate waxmaterial wherein a candle having a density at least as great as that ofa cast candle is obtained by subjecting the particulate material to acompressive force of at least 2,000 p.s.i.

Also an important object of the invention is to provide a compressionmolding process for forming a candle body having characteristicscomparable to those of a cast candle of the same size wherein theprocessing time is effectively lowered from time intervals approaching12 hours to a time of substantially less than one minute. a

A still further object of the invention is a method and apparatus as setforth in the foregoing objects wherein a high-melt, particulate wax canbe utilized to provide a candle of superior handling and storagequalities.

My invention also has as one of its objects a method and apparatus forforming a particulate material wherein the material is compressed andthereby coalesced into a self-sustaining body under a sufficiently highpressure to avoid the need for subsequent tempering, or otherstrengthening or forming steps.

Still another object of the present invention is a method and apparatusfor forming candles from a particulate material wherein the material iscompressed under a pressure of at least 2,000 p.s.i. to produce a candlehaving an even surface free of irregularities which exhibits superiorlight-reflecting properties.

It is also an object of this invention to provide a freestanding waxcandle formed by coalescing particulate material under a force of atleast 2,000 p.s.i. whereby the candle is substantially free of entrainedair as minute cellular voids or larger air pockets as well and as aresult thereof exhibits superior color characteristics and physicalstrength.

In the drawing:

FIG. 1 is a cross-sectional side view of the candleforming apparatus atthe assembly station;

FIG. 2 is an end view of the apparatus as it would appear at thecharging station with one of the candle molds being shown in crosssection and the other in elevation;

FIG. 3 is another side view of the apparatus as it would appear at thecompression station with one of the candle molds being illustrated incross section and the other in elevation;

FIG. 4 is an end view, similar to FIG. 2, illustrating the moldingapparatus at the ejection station where the candle blanks are removedfrom the molds;

FIG. 5 is a cross-sectional view of the completed candle blank; and

FIG. 6 is a perspective view of the completed candle.

Referring to the drawing, a plate 10 has a plurality of openings thereinfor receiving four open-ended, cylindrical die molds 12, two only ofwhich are depicted in essentially schematic form in FIGS. l4. It is tobe appreciated in this respect that any number of molds can be employed,limited only by practical production and engineering considerations.Each of the molds 12 is disposed in an upright position and has itslower end closed by a die plate 14. Each die plate 14 is provided with ahollow, open-ended spike hole form 16 which projects upwardly from thedie plate 14.

The upper end of each mold 12 receives a wick rod 18 for purposes to bemade clear hereinafter. The lower end of the wick rod is received withinthe spike hole form 16, and the upper end of the rod 18 is surrounded bya cap 22 which also engages the edge of the mold 12. A piston 24surrounds each of the rods 18 and is in frictional engagement with thelatter while still being free to move downwardly within the mold 12. Thematerial-engaging surface of the piston 24 in the form thereofillustrated is outwardly convex to produce a candle of one desiredconfiguration. The wax engaging face of the piston can be of any desiredconfiguration, e.g., flat, concave, provided with raised or indentedletters or other indicia, depending upon the nature of the candle bodydesired for a particular visual effect. Each of the molds 12 has anopening 26 in one side for receiving a charging chute 28 through whichparticulate wax material 30 is introduced into the cavity of the mold12.

The plate is supported for movement by a conventional conveyor (notshown) along a vertical support rail 32 disposed between a pair of angleplates 34, the latter providing a support for the die plates 14 disposedin the bottom of each mold 12. Each of the caps 22 preferably has threeapertures therein, and a compression rod 36 coupled with a pressure ram38 pass through each aperture respectively to actuate the piston 24 whenthe die mold assembly is moved to the compression station as illustratedin FIG. 3. As the of the air entrapped in the interstices of theparticulate wax. Generally, at least about 10 seconds up to 80 secondsis an effective compression period at the pressure specified above. Thisresults in complete coalescence of the particulate material30 into aselfsustaining body in the form of a candle blank 46. Finally, theconveyor moves the die molds 12 to the ejection station where ejectionrods 42 are inserted into each of the molds 12 and the ram 44 isactuated to continue the downward movement of the piston 24 and therebyeject the candle blank 46 from the lower end of the mold 12. The molds12 and their die plates 14 would then normally be returned to theassembly station along a continuous conveyor. As a result of thefrictional engagement of the piston 24-with the wick rod 18 as thepiston moves downwardly'within each of I the molds 12, the rod 18 isplaced under tension along molds 12 approach this station the supportrail 32 is of to rest upon a lower platen 40 beneath the ram 38.

At the ejection station, the three ejection rods 42 are coupled with asecond ram 44 which passes through respective apertures in each of thecaps 22 to eject a completed candle blank 46 from the lower end of eachof the molds 12. At this point, a pair of supports 48 parallel with therail 32 provide the necessary stabilization for the plate 10 whilepermitting the blank 46 to be ejected. As best illustrated in FIG. 5,the completed candle blank 46 conforming to one type of preferred candleconfiguration has a wick hole 50 and a spike hole 52 centrally disposedalong the longitudinal axis of the candle blank. The upper surface ofthe candle blank 46 illustrated as being concave as a result of theconvex configuration of the surface of the piston 24. The completedcandle 54 is obtained by inserting a candlewick 56 through the wick hole50 and securing the same by a knot or other appropriate retainer whichcan be lodged in the end of the spike hole 52 adjacent the wick hole 50.

In carrying out the method of the invention the die molds 12 are firstmoved to the assembly station shown in FIG. 1 where the die plates 14are inserted into the lower end of the molds l2 and the wick rods 18with the pistons 24 and caps 22 placed thereon positioned in therespective molds 12. It will be appreciated that once the lower end ofthe rod 18 is inserted within the spike hole form 16 and the cap 22placed upon the mold 12, the rod is restrained against lateral movementrelative to the mold. The conveyor (not shown) then moves the assemblyof the die molds 12 along the rail 32 to the charging station wherechutes 28 are positioned within the openings 26 and the particulate waxmaterial 30 is deposited within each of the molds 12.

Next, the conveyor moves the assembly of molds 12 along the rail 32 tothe compression station where the compression rods 36 are inserted intoeach of the molds 12. The material 30 is then subjected to a compressiveforce of at least 2,000 p.s.i. and sufficient to cause the particulatematerial to coalesce into a selfsustaining body by moving the pistons 24downwardly in a direction axially of the mold 12 under the force of theram 38. Preferably, the force exerted by the ram 38 is within the rangeof 4,700 to 6,000 p.s.i. with the higher pressure value being preferredand this force is maintained for a sufficient time to expel most if notall its longitudinal axis to preclude any movement of it and therebyassure that the resulting wick hole 50 is exactly positioned in thecenter of the blank 46 and is free of irregularities. The wick rod 18operates to forma centrally located aperture in the candle blank bodyfor receipt of a wick therein which then extends truly axially of thecandle. It is not feasible to compress the wax around a wick because thelatter would simply wad up in the mold cavity under the high pressureapplied'to particulate wax material in the mold. There is no tendencyfor this result to occur in connection with'the relatively rigid rod 18though since it is held by the wick rod holder as the. compressionpiston moves downwardly in the cavity and the forces thereon are evenlydistributed thereon. In order to reduce the amount of airentrapment inthe final candle blank, a vacuum of the order of 28 in. Hg belowatmosphere may be pulled on the mold cavity during compression moldingat a point above the level of the powder introduced into the mold.

The preferred particulate wax material tobe used in the specific processdetailed above comprises a major proportion of paraffin having a meltingpoint of at least about (measured with a Perkin-Elmer differentialscanning calorimeter). This relatively high melting material results ina candle which can be shipped and stored without danger of warpage as aresult of excessiveheat. Generally, the wax material will have a meltingpoint within the range of 124 to 154 F. Compressed candles produced fromthese wax materials offer a very good surface finish without the cost ofhighly polished molds. It is to be understood though that this inventionis not limited to that particular wax composition, and other candleformulations may be employed so long as the particles thereof may besubstantially coalesced under pressure to produce a selfsustaining bodywhich gives the appearance of having been cast and burns withessentially the same properties as a cast candle. The particulatematerial can be prepared in any conventional manner although optimumresults are obtained when initially liquid paraffin or equivalentmaterial is sprayed through a nozzle into the atmosphere and allowed tosolidify into particles having a size of from 0.5 to 300 microns indiameter. Any of the conventional pigments and dyes now in use forcoloring the wax used in casting candles may be used in the presentcompression molding process. In the above, it has also been founddesirable to incorporate at least 0.5 percent by weight of stearic acidas a vehicle in those cases where a coloring pigment is added to thewax. Other additives such as fatty acid esters (C to C fatty alcohols (Cto C ethyl alcohol and fatty amides (C to C may also be introduced intothe wax formulation to enhance the appearance, processing ease orphysical characteristics of the final product. The amount of additive tobe introduced may be varied depending upon the nature of the candleproduct to be produced. For example, usually about percent of stearicacid is the useful upper limit thereof. The method is also advantageousfor producing polychromatic candles by introducing into the molds layersof different colored particulate material or blends of large particlesof various colors. ln addition, appropriate dividers which extendlongitudinally of the molds 12 can be utilized to permit theintroduction of different colored wax materials with the resultingcandle having colors which extend longitudinally of it.

In forming a candle according to the above described method, completecoalescence of the particulate material is obtained as a result of thehigh compressive force applied. This complete coalescence removes theneed for tempering or further forming steps and the resulting candle isa self-sustaining, freestanding body with superior physicalcharacteristics. The high compressive forces utilized in the instantinvention result in a completely homogeneous candle body as contrastedwith candles previously made by compression molding which did not havethis property. It is this ability to obtain complete homogeneity whichmakes the method of the present invention particularly adapted toobtaining colored candles by using colored wax to a degree notpreviously possible. In addition, the complete coalescence of theparticulate material results in an even candle surface with superiorlight-reflection characteristics and hence more vivid color. Thevividness of the colors of candles produced in accordance with thisinvention is believed to be attributable in large measure to the lack ofsignificant air entrapment in the final compression molded blank. Air isan excellent light scattering medium and thus it is essential that it beeliminated from the candle body if the color thereof is to be equivalentto a cast candle where air entrapment is not a problem. However, it wasunexpectedly discovered that particulate wax could be compressed in ashort period of time at pressure above 2,000 p.s.i. and obtainsubstantially complete coalescence of the wax and consequent expulsionof air from the candle blank.

While it was previously felt that high compressive forces should not beutilized in the compression molding of candles from particulate waxmaterial because of the danger of forming discontinuities in thefinished candle, the unexpectedly superior candle which is obtained bythe method of the present invention is directly attributable to theextremely high pressure utilized. While there is no upper limit on themagnitude of the compressive force which can be utilized in the methodof the invention except from the standpoint of practical commercialoperation, it has been found that no significant product improvement isobtained above about 10,000 p.s.i.

It is contemplated that the invention will find use in candles of allsizes although it is particularly advantageous when employed toconstruct a candle of at least 3 inches in diameter and 9 to 12 inchesin length. Such a candle, when constructed in accordance withconventional casting techniques, would require at least 3% hours to coolafter the molten material was introduced into the mold. This coolingstep is completely eliminated in the method of the present inventionwhile still obtaining a candle having a density at least as great asthat of the cast candle.

While one specific embodiment of the invention has been illustrated anddescribed in detail, it is to be understood that an infinite variety ofshapes and sizes of candles can be produced in accordance with theteachings hereof. For example, raised or depressed designs may be formedby providing a separable mold having appropriate design definingdepressions or raised areas in the mold surfaces. Similarly, the pistonand bottom closure faces may be of different shapes as desired andprovided with raised or depressed designs or lettering.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. A method of making candle blanks from a particulate wax material in amold therefor, said method comprising the steps of:

depositing a quantity of said material into said mold;

subjecting said material in the mold to a compressive force of at least2,000 p.s.i. and sufficient to cause the particulate material to beformed into a selfsustaining body; and

removing said body from the mold.

2. A method as set forth in claim 1, wherein said step of subjecting thematerial to a compressive force includes maintaining said compressiveforce on said material. for a predetermined time sufficient. to expelsubstantially all of the air initially entrapped in the space betweenthe particles of wax.

3. A method as set forth in claim 2, wherein the step of maintainingsaid compressive force on the material for a predetermined time includesapplying such pressure to the quantity of material for a time intervalof from about 10 to seconds.

4. A method as set forth in claim 2, wherein said step of subjecting thematerial to a compressive force includes applying a compressive force ofabout 6,000 p.s.i. to said material.

5. A method as set forth in claim 1, wherein said mold is of cylindricalconfiguration and the step of compressing the material comprisesapplying force thereto in a direction axially of the mold.

6. A method as set forth in claim 1, wherein said material is initiallycomprised of particles having a size of from 0.5 microns to 300 micronsin diameter.

7. A method as set forth in claim 1, wherein is included the step offorming a wick hole in the candle blank simultaneously with subjectingthe material to a compressive force.

8. A method as set forth in claim 7, wherein saidmold includes a wickrod disposed therein and said step of forming a wick hole includesdepositing said material around the wick rod; and maintaining said rodunder tension along its longitudinal axis as said material is subjectedto said compressive force whereby movement of said rod relative to saidmold is precluded.

9. A method as set forth in claim 1, wherein said material comprises amajor proportion of parafiin having a melting point within the range of124 to 154 F.

10. A method as set forth in claim 9, wherein said particulate materialincludes a colorant for imparting a color thereto.

11. A method as set forth in claim 10, wherein said material includes avehicle selected from the group consisting of C to C fatty acids, fattyacid esters, fatty alcohols, and fatty amides.

12. A method as set forth in claim 10, wherein said material includes atleast 0.5 percent by weight of stearic acid as a vehicle for saidcolorant.

13. A method as set forth in claim 1, wherein is includes the step ofpulling a vacuum on the area of the mold above that initially occupiedby the material during compression molding of said body.

14. A method as set forth in claim 1, wherein is included the steps ofproviding a separable mold and forming design defining depressions orraised areas in the candle forming surfaces thereof.

15. A method of making a candle from a particulate wax material in anopen-ended, tubular mold therefor, said method comprising the steps of:

placing the mold in a loading position;

closing one end of the mold;

depositing a quantity of said material into said mold;

inserting a pressure piston into said mold from the other end thereof; I

moving said piston toward the material to place the latter under a forceof at least 2,000 psi. to cause the particulate material to. be formedinto a selfsustaining body;

opening said one end of the mold; and

continuing movement of said piston in a direction to eject said candlefrom said one end of the mold.

16. A method as set forth in claim 15, wherein is included the step ofpositioning a wick rod in the mold prior to said depositing step to forma wick hole in the body.

17. A method as set forth in claim 16, wherein is included the step ofmaintaining said piston in frictional engagement with said rod as thepiston moves under said compressive force to place said rod undertension along its longitudinal axis and preclude movement of the rodrelative to the mold.

18. A method as set forth in claim 16, wherein is included the step offorming a spike hole in said material as the latter is coalesced intosaid body.

19. A method as set forth in claim 16, wherein is included the step ofinserting a Candlewick through said wick hole in the body.

1. A method of making candle blanks from a particulate wax material in a mold therefor, said method comprising the steps of: depositing a quantity of said material into said mold; subjecting said material in the mold to a compressive force of at least 2,000 p.s.i. and sufficient to cause the particulate material to be formed into a self-sustaining body; and removing said body from the mold.
 2. A method as set forth in claim 1, wherein said step of subjecting the material to a compressive force includes maintaining said compressive force on said material for a predetermined time sufficient to expel substantially all of the air initially entrapped in the space between the particles of wax.
 3. A method as set forth in claim 2, wherein the step of maintaining said compressive force on the material for a predetermined time includes applying such pressure to the quantity of material for a time interval of from about 10 to 80 seconds.
 4. A method as set forth in claim 2, wherein said step of subjecting the material to a compressive force includes applying a compressive force of about 6,000 p.s.i. to said material.
 5. A method as set forth in claim 1, wherein said mold is of cylindrical configuration and the step of compressing the material comprises applying force thereto in a direction axially of the mold.
 6. A method as set forth in claim 1, wherein said material is initially comprised of particles having a size of from 0.5 microns to 300 microns in diameter.
 7. A method as set forth in claim 1, wherein is included the step of forming a wick hole in the candle blank simultaneously with subjecting the material to a compressive force.
 8. A method as set forth in claim 7, wherein said mold includes a wick rod disposed therein and said step of forming a wick hole includes depositing said material around the wick rod; and maintaining said rod under tension along its longitudinal axis as said material is subjected to said compressive force whereby movement of said rod relative to said mold is precluded.
 9. A method as set forth in claim 1, wherein said material comprises a major proportion of paraffin having a melting point within the range of 124* to 154* F.
 10. A method as set forth in claim 9, wherein said particulate material includes a colorant for imparting a color thereto.
 11. A method as set forth in claim 10, wherein said material includes a vehicle selected from the group consisting of C12 to C26 fatty acids, fatty acid esters, fatty alcohols, and fatty amides.
 12. A method as set forth in claim 10, wherein said material includes at least 0.5 percent by weight of stearic acid as a vehicle for said colorant.
 13. A method as set forth in claim 1, wherein is includes the step of pulling a vacuum on the area of the mold above that initially occupied by the material during compression molding of said body.
 14. A method as set forth in claim 1, wherein is included the steps of providing a separable mold and forming design defining depressions or raised areas in the candle forming surfaces thereof.
 15. A method of making a candle from a particulate wax material in an open-ended, tubular mold therefor, said method comprising the steps of: placing the mold in a loading position; closing one end of the mold; depositing a quantity of said material into said mold; inserting a pressure piston into said mold from the other end thereof; moving said piston toward the material to place the latter under a force of at least 2,000 p.s.i. to cause the particulate material to be formed into a self-sustaining body; opening said one end of the mold; and continuing movement of said piston in a direction to eject said candle from said one end of the mold.
 16. A method as set forth in claim 15, wherein is included the step of positioning a wick rod in the mold prior to said depositing step to form a wick hole in the body.
 17. A method as set forth in claim 16, wherein is included the step of maintaining said piston in frictional engagement with said rod as the piston moves under said compressive force to place said rod under tension along its longitudinal axis and preclude movement of the rod relative to the mold.
 18. A method as set forth in claim 16, wherein is included the step of forming a spike hole in said material as the latter is coalesced into said body.
 19. A method as set forth in claim 16, wherein is included the step of inserting a candlewick through said wick hole in the body. 